SmogRank / Hartford / Mecca

Hartford vs Mecca: PM2.5 compared

Over the last year, Mecca's air was about 2.4× as polluted as Hartford's: PM2.5 averaged 12.1 µg/m³ against 5.0, on the 80 days both cities were measured. Mecca had the dirtier air on 60 of those days, Hartford on 20. Mecca was over the WHO's daily guideline of 15 µg/m³ on 25 of them, Hartford on 1.

Right now

Hartford#1,920on the 24-hour board of 2,002, at 12 US AQI (2.2 µg/m³)
Mecca#87on the 24-hour board of 2,002, at 77 US AQI (23.1 µg/m³)

The last year, day by day

Hartford
Mecca
Each city's daily mean from 7 Oct 2025 to 6 Oct 2026, one stripe a day, coloured by band. A blank stripe is a day without a daily mean.

Month by month

Nov2025DecJan2026FebMarHartford, Apr 2026: 5.2 µg/m³Mecca, Apr 2026: 6.7 µg/m³AprHartford, May 2026: 5.7 µg/m³Mecca, May 2026: 16.9 µg/m³MayJunJulAugHartford, Sep 2026: 4.3 µg/m³Mecca, Sep 2026: 11.5 µg/m³SepOct
Monthly means in µg/m³ over the days both cities were measured. Solid: Hartford. Faded: Mecca. A month shows once both share 10 such days. Dashed line: the WHO daily guideline, 15 µg/m³.

Each city's worst days

Hartford

Mecca

Daily means in US AQI, with µg/m³ beside them, since the index stops at its top value, over the days both cities were measured in the last year. Each date opens that day's world board.

Compare either city with another

Hartford

Side by side with Waterbury (the nearest), Gujranwala (the world's worst on 30 days).

Mecca

Side by side with Indio (the nearest), Hanford (United States's 2nd worst on 30 days), Gujranwala (the world's worst on 30 days).

Use this page

SmogRank, PM2.5 daily means compared, Hartford and Mecca, 7 Oct 2025 – 6 Oct 2026, smogrank.com/compare/us-hartford/us-mecca (accessed 7 Oct 2026).

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

The same rules as every SmogRank figure: reference monitors first, and a day counts with 18 measured hours. How we measure.

Updated 2026-10-07 08:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.